Robert Husband: taking a big look at the small world of mites

Written by David Green.

“Man is certainly crazy. He could not make a mite, but he creates gods by the dozens.”

—Montaigne

By DAVID GREEN

Consider the scale of life, from what we see in our daily routine down to the minuscule; from our fellow humans and the various creatures of the planet down to that which can’t be seen by normal vision.

Start with a dog, for example, then take a closer look and discover another level of life in the form of the flea.

But don’t stop there. The flea is such a small beast on its own, but hoist it onto the stage of a microscope and there’s a whole new level of life to discover.

Retired Adrian College professor Robert Husband holds in front of him a photo of a flea. It’s a flea with scales, and under the scales he can see eight mites. There are probably more on other parts of the tiny insect.

Man creates gods by the dozens, says Montaigne, and Dr. Husband discovers mites by the dozens. Over the past 30 years, he’s identified more than 100 animals entirely new to science.

When he goes to his mailbox, he might find a package from Japan or Brazil, from the Philippines, Bangladesh or Costa Rica. Inside he’ll find a cockroach or a beetle or a bumble bee, and on each he’ll discover mites.

During his years as a biology teacher at Adrian College, Dr. Husband published a couple scientific papers a year, on the average. Most of his work with mites was restricted to the summer so it didn’t interfere with teaching.

Since retiring in 1997, mite research has moved to the forefront. He’s producing about five papers a year with titles such as these: A new species of Eutarsopolipus from Georgia; A new species of Chrysomelobia from Australia; Two new species of Dorsipes from Germany.

So many mites; so little time. There’s so much yet to learn.

Fame in his Field

When Robert Husband first considered becoming acquainted with mites, he didn’t really know what he was getting into. He was working on a doctorate at Michigan State University and a professor suggested the study of mites.

“The major professor who was to guide my research suggested the study of mites offered a lot of challenges because not many people had done much,” Dr. Husband said.

Considering the potential number of mite species—perhaps hundreds of thousands—the field was wide open.

“I thought he was talking about some sort of gnat and wondered why anyone would want to study little flies,” he recalls. “I soon learned.”

He started out on the wrong foot, looking for mites found on the reptiles and amphibians of Michigan. He was too far north. There isn’t an abundance of lizards in this part of the country and he never found a single specimen.

Running out of money and with a third child on the way, Dr. Husband went on active duty with the Michigan Air National Guard for six months.

When he returned, he redirected his studies toward mites found on insects. Now he had the opposite problem from his first foray—too many mites. They’re everywhere. Eventually, he narrowed his work to one family of mites, the Podapolipidae. That’s where he stayed and that’s where he’s gained recognition as a world leader in mite research.

Last fall at a meeting of arcologists—scientists who study mites and ticks—Robert Husband was presented an award for his life-long contributions to the field.

It’s a lonely field to stand in. More than 30 years ago, Dr. Husband was told by a colleague that few would ever appeciate his work. He would spend hours identifying species never before known by man, but not many people would admire his efforts.

His labors wouldn’t result in a promotion or merit pay or local recognition.

“He told me, ‘If you are not studying these animals because you enjoy it and get a feeling of contributing to your discipline, then spend your summers and spare time playing golf or whatever you enjoy.’”

He wasn’t completely right, because Dr. Husband’s research did become known on campus and he received a lot of help collecting specimens from colleagues.

“Still, he was correct in recognizing that the main reason for working on research of any kind is the satisfaction of contributing something to the knowledge of the field,” Dr. Husband said. “Future workers in the field will benefit from these efforts.”

At the arcologist conference last year, the comment was made that Dr. Husband knows more about the family Podapolipidae than anyone else on the planet.

Maybe so, he says, but that’s nothing on which to rest your laurels.

“What I know is a small fraction of what there is to know about this family of parasitic mites.”

So it’s back to the microscope. There are measurements to be taken, tables of data to be constructed, drawings to be finished. And there are billions of mites out there riding on the backs of millions of bumblebees.

Mites are everywhere

Ubiquitous.

That’s a good word to describe the habitat of the mite.

From mountain tops to ocean depths, and all the territory in between, mites are living most everywhere.

“Mites are certainly ubiquitous, but I’d hesitate to say that every living thing has mites,” Dr. Robert Husband said.

Most common animals have mites from time to time, and that includes humans. Spiders, clams, snakes turtles and frogs—they’ll all encounter mites in their lives, perhaps without ever knowing it. There are even aquatic mites that feed off crustaceans or ride along on the larva of mosquitoes.

Humans spend a lot of time with mites, but fortunately, they seldom know it.

“Soil mites and house dust mites crawl off and on humans,” Dr. Husband said, “but most of the time they’re not really hurting anything and not noticed.”

The same cannot be said for insects carrying parasitic mites. They generally pierce the soft membranes of the host insect, or crawl up through the spiracles (similar to a mammal’s nostril) and pierce the walls of the air sacs to get at the body fluids.

Some mites have other clever schemes. Dr. Husband examined a cockroach from Australia and found a mite that secreted a substance to dissolve a hole through the tough outer covering of the roach.

Although mites are generally considered pests, they often play a beneficial role. There’s an acarid mite, for example, that lives in the nests of bumblebees and feeds on roundworms that feed on the bees. The mites also feed on a fungus that, if not kept under control, would overrun the nest.
In general, mites are beneficial decomposers that play a key role in maintaining life as we know it. Mites break down organic matter which allows it to used once again by plants. For some species, life with mites is misery. But in the larger scheme of things, life without mites would be impossible.

Peering through the microscope

The systematic study of mites dates back to 1758 when Linnaeus described Acarus siro.

Today, more than 30,000 species of mites and ticks are known and scientists believe there must be half tens of thousands more.

Dr. Robert Husband, at his home laboratory, has about 400 vials containing thousands of his speciality, the podapolipid mite. He also has about 3,000 mounted on slides.

The specimens come from insects he’s collected or from those friends and colleagues have acquired. In addition, packages arrive from around the world with new samples to investigate.

Acarus siro, the grain mite.that The smallest known mite measures less than a tenth the thickness of a dime. The specimens Dr. Husband studies aren’t all that tiny, but if a dozen easily fit on a flea, then all the work takes place under a microscope.

“Identifying new mites is vaguely analogous to recognizing a person in your church, club or school as new,” Dr. Husband says. “You need to have a familiarity with the members of your group to pick out someone new.”

That means he needs to know all 204 members of the family, from young to old, and recognize there’s some variation.

“People don’t always wear the same clothes or have the same hair styles,” he said. “Mites have some variation within the species, too.”

A typical study session might follow this pattern.

Take a specimen that arrived in the mail—a long horn beetle from the Philippines, for example—and place it in a beaker of warm water to return some flexibility to the long-dead insect.

Place the specimen under a microscope, spread the wings, and scrape off some mites.

With luck, they’re members of the podapolipid family.

Mites aren’t the only items to be found.

A researcher might encounter a species of beetle on another beetle. There could be tiny round worms and pseudoscorpions. If the host beetle is one borrowed from a university collection, all these other tiny beasts must be collected and sent back with the beetle.

When Dr. Husband collects a few of the mites he’s seeking, he mounts them on slides and completes extensive labeling on each one. Then the real work begins. He’ll take about 100 measurements to document the characteristics of males and females at various stages of development.

He’ll measure mouth parts and setae (the hairlike appendages that work something like fingers for a mite). He’ll check on the number of leg pairs. He’ll look at the position of legs and the location of copulatory organs.

He’ll see if stigmata are present. Some mites breathe through these, others breathe through the skin. He’ll measure the plates of the thorax and note whether or not they’re split.

Trying to measure so thoroughly forces him to look closely at each specimen. It’s essential in determining whether or not he’s looking at something completely new.

Dr. Husband says there are 25,000 known species of ground beetles in the world, and members of podapolipidae have been found on 131 of them. That’s 131 and counting. The opportunities for research are seemingly endless.

It’s fulfilling to work in partnership with a scientist from Japan or one from Germany, but there’s no need to travel that far to learn something new about mites. There’s plenty that could be discovered in the distance between Adrian and Morenci.

“We don’t even know everything in our own area, let alone running off to the Philippines,” he said.

And the work is far from static. Something that’s caught his fancy recently is the possibility of finding mite exoskeletons in the bodies of grasshoppers trapped in glaciers.

He’s done some preliminary studies from Alpine meadows and he thinks he might be on to something.

“The potential is good,” he said. “I’ll keep looking.”

Married to Mites

Marry a farmer, you end up doing the chores. Marry a politician and you’re thrown onto the public stage.

For Dr. Robert Husband, it’s not possible to overemphasize the contributions of his wife and children.

“As soon as our children could walk, they were looking for insects which could have mites,” Dr. Husband said.

Family assistance doesn’t stop with the collection of specimens. The spouses and children of scientists often provide moral support, as well as financial backing to projects that don’t bring in any income—such as the study of mites.

Dr. Husband sees his wife, Patricia, as taking a role that goes far beyond the typical wife of a scientist.

“I know of no spouse of a living acarologist who has climbed mountains, crossed oceans, worked side by side in museums around the world, and has been involved to the extent of co-authorship of papers resulting from studies of mites as my wife has.”